Calculating machine



MUL 77/DZ. /CA ND Sept. 24, 1'946.

FENCE D. BROIDO qALcULATINe MACHINE Filed Jan. 13. 1944 coNvfRs/o/v naze. l

MUL T/PL/ER DENOM/NA 770A/ F/GS. Pou/vos coNvERs/ON M2115.

16 shuts-Shoot. 1

/opoopoo l0 MULT/PL/ER DENOM/NA 770A/ .SH/FT 4 s -2 o +2 +3 +4- 7&5 .26 +7 i* 1 N w m '0 m Q. E 'Q 'Q Q 9 Q Q Q Q Q Q Q l! I: n n u u n u `u u lu e 2 o g Q of o O" o' Q g 8 g Q, Q Q o Q Y( G O Q o k Q o 0 D d s 0f s. of @7,000 /ooqo 0.024 0.24 2.4 2 /o /00 '/0 fo@ /0- 2 01046 0.45 4.8 4 20 200 2 20 200 2 .20 Q 5 00720.72 7.2 6 5 3o 500 s so 50o s a0' 4- 0.096 0.96 9.6 e 4 40 40o 4 4o 40o 4 4o Q5 0./2 L2 /0 /0550 500650 5005 50 5f 6 0./44 A44 2,4 /2 6 6oY 60o e @so @oo 6 60 R 7 0./6@ sa 4.6 /4 '7 70 70o 7 7o Foo 7 7o 8 0./92 A92 7.2 /s e .eo aco a @o @no 5 olmmr 9 0.2/6. 2./6 9.5/8 s 9o 30o e Q0 QQ Qc 32%.

16 Sheets-Sheet 3 F764. FRxcr/o/vs m.. B .M m y Y w o C M UL T/PL /ER DENOM//YA T/ON Q H 0006000 O\ lSept. 24, 194s.

D. BROIDO CALCULATING vMACHINE Filed Jan.

I n oentog W Attarncy Sept. 24,71946.' D. BROIDO CALCULATING MACHINE,

Filed Jan. '13. 1944 I 1e sheets-sheet 5 www M Attorney 24, 1946. D. BROIDO CALCULATING MACHINE Filedv Jan. 13, 1944 16 Sheets-Sheet 6 f .5 f V4.

///X///V/////Y Sept. 24, 1946o D; BRolDo CALCULATING MACHINE Filed. Jan. 13, 1944 F G A..

-1 Sheets-Sheet 7 Sept 2,4, 1946. D. BRolbo 2,408,134

, l GALCULATING ummm:

Filed Jan. 1s, 1944 1e sheets-snee# s F/ G7, L/owPLv'wOL/osuosuouows I n uen {or y Attorney Septg 24, 1946. D. BROID@ CALCULATING MACHINE Filed Jan. 13, 1944 16 Sheets-Sheet 9 D; BHOID@ CALCULATING MACHINE Filed Jan. l5, 1944 16 Sheets-Sheei'l lO Sept. 24,194@ 9D. BND@ 408,134

GALCULATING MACHINE Filed Jan. 13, 1944 16 sheets-sheet 11 U07 1/061/051/041/03L/02 L/o 1 s/o o/6 Sept. 24, 1946.v 5mm@ 408,134

CALQULATNG MACH-INE Filed Jan. l5', 1944 16 Sheets-Sheet l2 l f Attorney y Sept 24, 194s.

D. BROIDO Filed Jan. 13, 1944 CALCULTING 'MACHINE Homey 16 Sheets-Sheet l5 Sept., 249 D. www@ CALCULAIINGrI MACHINE Filed Jan. 13, 1944 F/Gp/Z.

` 16 Sheets-Sheet 14 In vanm- B ,yf

sept. 24, 194e: D. BROIDO 2,408,134

GALCULATING MACHINE Filed Jan. 13, 1944 1e sheets-sheet 15 F/ G13. o

W :ff 4 f Attorney Sept. 24, 194u D. '@RQID@ 2940@ 34 CALGULATING MACHINE Filed Jan. l5, 1944- 16 Shee'tS-Shee'i: 16`

Attorney Patented Sept. 24, 1946 UNITED STATES PATENT OFFICE Application January 13, 1944, Serial No. 518,044 In Great Britain October 21, 1942 16 Claims. l

This invention relates to calculating machines for non-uniform numerical systems comprising interrelated sets of units (such as pounds sterling, shillings and pence).

The object of the invention is to provide a relatively simple calculating machine of the repeated addition type for calculations involving non-uniform numerical systems, the results being correctly expressed in a non-uniform system.

A further object is to provide a calculating machine for non-uniform systems which at once converts all set-up values into all decimal multiples (within the capacity of the machine) eX- pressed in the non-uniform system.

Yet another object is to provide a calculating machine for ncn-uniform systems with a minimum number of physical representations of decimal multiples of the set-up values by enabling a representation of a digit of a decimal set of units to cooperate selectively with several denominational registering elements of this set of units.

Still a further object is to provide a calculating machine for non-uniform systems with a minimum number of settable selector elements, only one element being required to represent all decimal multiples, within the machine capacity, of each set-up value.

Another object is to provide a calculating machine for non-uniform numerical systems adapted to enter any desired decimal multiple of the setup factor directly from the settable selector elements into the result register during each working cycle.

A further object is to provide a calculating machine adapted for direct division in non-uniform numerical systems- Further objects of the invention will become apparent as the description proceeds.

In the accompanying drawings which illustrate a machine made according to the present invention:

Figure l is a pence conversion table,

Figure 2 is a shillings conversion table,

Figure 3 is a pounds conversion table,

Figure 4 is a conversion table Ifor fractions of a penny,

Figures 5 and 5A together constitute a front elevation of the machine,

Figures 6 and 6A together constitute a vertical section taken approximately on line VI-VI of Figure 5A,

Figures 7 and 7A together constitute a horizontal section approximately on line VIL-VII of Figures 5, 5A,

Figure 8 is a partial section approximately on line VIII-VIII of Figure 6,

Figure 9 shows diagramatically some of the selector plates used in the machine,

Figure l0 shows selector plates of the upper bank,

Figure l1 shows selector plates of the middle bank,

Figure 12 shows selector plates of the lower bank,

Figure 13 shows selector plates for fractions of a penny used in a modification of the invention,

Figure 14 is a partial section through the result register, taken approximately on line XIV- XIV of Figure 6A,

Figure 15 is a section on line XV-XV of Figure 14,

Figure 16 is a partial Vertical section approximately on line XVI-XVI of Figure 6A,

Figure 17 is a partial view in the direction of arrow XVII in Figure 5, and

Figure 18 shows some selector plates suitable for use in a modication.

General arrangement The machine illustrated in the drawings comprises, broadly, a shiftable set-up and conversion mechanism, a result register, a feeler mechanism adapted to transfer the set-up values to the result register, a revolution register for indicating the number of said transfers, and driving means and other associated devices. As shown in Figures 6, 6A, and 7,' 7A, the various mechanisms are mounted on a base plate I in the frame structure 2, 3, and are protected :by a cover 4.

Set-up and conversion mechanism As shown in Figures 5, 5A, 6, 6A, and 7, 7A, the set-up mechanism comprises nine setting levers 5, of which iive levers are reserved for the pounds denominations (designated LIN-LI), one for the shillings (S), one for pence (DI), and two levers for tenths and hundredths of a penny, respectively (DHV-l, DID-2), All setting levers 5 are rockably mounted on a shaft 6 iiXedly supported in side plates 'I, 3 of a carriage 9. Forward extensions of levers 5 protrude through slots in carriage cover I0 so as to be rocked into alignment with numerals arranged along the respective slots to indicate the set-up values. Each lever 5 has serrations I I co-operating `with detente I2 rockable on a rod I3 secured in carriage plates "I, 8. Springs I4 hold the detents I2 in engagement with serrations II, guide plates I5 serving to prevent the detente from slipping oli the serrations.

Setting levers 5 serve to bring into working position selector plates I6, one of which is provided for each numeral marked c-n carriage cover l adjacent to the respective slots. These selector plates, which constitute the conversion mechanism and will be fully described hereafter, are arranged in three banks clearly shown in Figure 6. The middle bank comprises LIBZ, S, and D-2 selector plates lE which are rockably supported o-n shaft S by the respective setting levers 5 and bails Il (Figures 7, 7A). The upper bank comprises m03, Li, and D50-1 selector plates I6 mounted in bails i9 rockable on shaft I9 secured in carriage plates ll, 8. One of the bails i8 supporting each set of plates I@ is connected by a link 29 to the respective setting lever 5 on shaft li. The lower bank comprises Ll04, L10, and Dl selector plates l5 mounted in balls 2l rockable on shaft 22 and connected by links 23 to respective levers 5. Selector plates I6 coact with three banks of sensing pins 24 mounted for horizontal movement opposite the respective banks of selector plates. By aligning the setting levers 5 with certain numerals on carriage cover I9, the corresponding selector plates IG are brought into working position opposite the sensing pins 24 of the respective bank.

A restoring 4bar 25 p-ivoted on shaft 0 has a plate Z6 protruding through a slot in carriage cover l0. When knob 2l' nxed to plate 25 is lifted upwards, bar 25 rotates around shaft E and restores all setting levers 9 into the initial position..

Carriage 0 is mounted for transverse movement on rollers 29 running in rails 29, 39. A spring 3| mounted in barrel 32 runs over pulley 33 (Figure 7) and is secured to carriage plate 8, so as to pull the carriage to the left. An escapement pawl 34 pivoted in carriage base 9 co-acts with a rack 35 fixed to base plate l. A shift lever 36 pivoted at 'l' in carriage base 9 protrudes forwardly through a slot in carriage cover i9 and has a knob 39; spring 39 tends to rock the lever 3E clockwise as viewed in Figure 6. As shown in Figure 8, the rear end of lever 36 engages a slot in pawl 34, thus rocking it anti-clockwise so that a nose 49 formed on pawl engages the teeth of rack 35. When knob 39 is depressed, the rear end of lever 39 swings the pawl 34 clockwise as viewed in Figure 8, thus disengaging the nose 4I] from rack 35; the carriage is then shifted by spring 3l approximately half a step to the left, whereupon a second nose 4l on pawl 34 engages the rack, When kno-b 39 is released, lever 36 and pawl 34 are restored by spring 39, and nose I4l disengages rack 35, whereupon the carriage is again shifted for approximately half a step until nose 4l! re-engages rack Thus, the total movement of the carriage 9 upon each depression of knob 9B equals the pitch of rack 35. lThe carriage is arranged to move a maximum of seven steps to the left from the initial position, and four steps to the right thereof. Each step of the carriage is equal to the distance between two adjacent register wheels of the pounds set of units, as will be fully explained hereafter. As shown in Figures 5, 5A, the various positions of the carriage are indicated by a pointer `42 formed on machine cover 4, which pointer co-acts with numerals +1 to -l-'l on carriage cover I0 to indicate positions to the left from the initial position designated 0, and with numerals -1 to -4 to indicate the shift to the right.

Return movement of carriage 9 is effected by knobs 43 on a hand wheel 44 protruding through a slot in machine cover 4. Hand wheel 44 is fixed to a gear 45 secured to one of rollers 28. Gear 45 meshes with a rack 46 formed on front rail 29. By turning the hand wheel 44 clockwise (as viewed in Figure 5A) the carriage 9 is shifted to the right.

The carriage shift is utilised to multiply the set-up values by decimal multiples, i. e. by 10, 100, 1000, and so forth when shifted to the left, or by 0.1, 0.01, and so forth when shifted to the right. This arrangement of the set-up mechanism provides, in the present embodiment, for a capacity up to 99, 999, 999.9999 for the multiplier, and up to 99,9991l9z11-99d. for the multiplicand. The product may comprise thirteen pounds denominations, two shillings denominations, pence denomination, and six denominations of decimal fractions of a penny. A sensing pin 24 is provided for each bank of selector plates l5 for each of these twenty-two possible result denominations. The transverse distance between the sensing pins 24, as may be seen from Figures 9 and 7, is the same (namely, equal to the carriage step) between the pins associated with LI D11- Li and DI 0-1D| 06 denominations, but it is different to the distance between sensing pins LI, SIG, SI, Dl, and Dl01. More explicitly stated, the distance between sensing pins of any two non-decimal denominations (tens of shillings, units of shillings, or pence) is different from the carriage shift or any whole multiple of the carriage shift. Similarly, the transverse distance between the sensing pin of a non-decimal denomination and the sensing pin of any decimal denomination (pounds or decimal fractions of a penny, respectively) is dilferent from the carriage shift or any who-le multiple thereof. Further, the transverse distance between any sensing pins of a decimal notation (pounds) and of another decimal notation (decimal fractions cf a penny) is also different from the carriage shift or any whole multiple thereof. On the other hand, the transverse distance between any two adjacent sensing pins associated with the same decimal notation (pounds or decimal fractions of a penny, respectively) is substantially equal to the carriage shift. The importance of this arrangement will become apparent as th'e description proceeds.

Selector plates l0, except those reserved for the zero values, are notched so as to represent the converted decimal multiples of the respective set-up Values, that is the products of the set-up value by successive powers of l0, expressed in the interrelated denominations. The arrangement of these notches will be evident from an inspection of Figure 9. It shows three selector plates l 6 of the lower bank, namely those associated with 40,000, 10, and 3d., designated respectively Ll04(4), L|0(l), and D! (9). Sensing pins 24 are represented by thick vertical lines designated LI911-D|0"2 in the upper half of the drawing (which serves to illustrate the carriage shift to the left), and Ll07-Dll3-6 in the lower part (which illustrates carriage shift to the right). The transverse positions of the carriage are de.,- ignated by numerals 0 to +7 and -1 to -4 along the right-hand edge of the drawing. Selector plates I6 in line with each of these numerals are shown in their actual positions relatively to the sensing pins 24 in the respective transverse positions of the carriage.

Considering rst the pence selector plate DI (3), it will be seen that in the initial position 0 only one sensing pin 24 will be aligned with a notch in the plate, namely the DI pin; the depth of this particular notch is such as to represent 3, i. e., it is three unit steps deep, as indicated by the numeral 3 adjacent to this notch. The sensing pins 24 are arranged to move into the notches and to transfer the values associated with each notch to the corresponding numeral wheel of the result register, as will be fully described hereafter. Evidently the amount of movement of each sensing pin, viz., the amount transferred to the respective register wheel, is determined by the depth of the respective no-tch. If a, sensing pin does not encounter a notch, i. e., is stopped by the edge of the selector plate, it does not move appreciably, and the associated register wheel is not operated at all. In the present case, only the DI pin will enter a notch, and thus it will transfer the value 3 associated with this notch to the pence wheel of the result register.

When the DHS) selector plate is shifted one step to the left into position +1, sensing pins Sl and DI will be aligned with notches representing 2 and "6 respectively; consequently, the amount 2/0d.=3d. 10 will be entered into the register. When the selector plate is in position +2, the Ll and Si pins will be aligned with notches l and "5 respectively, and the amount 1:5:0=3d. 100 will be registered. Similarly, when the selector plate is in position +3, the amount 12:10:0- 3d. 1000 will be registered by pins LI'U, Li, and S10 entering notches 1, 2, and l respectively. When the plate is in position +4, the amount 125:0:0=3d. 10,000 will be registered by pins Ll02, L and L! in cov-operation with notches 1, 2, 5, respectively. These same notches operate, when the plate is shifted into position +5, +6 or +7, the respective pins of the next higher denominations so as to register l250:0:0=3d. 100,000; 12,500 =3d. 1,000,000; and 125,000=3d. 10,000,000, respectively, since, as already mentioned, the transverse distance between two adjacent sensing pins associated with pounds register wheels equals the transverse step of the carriage. It will now be seen why the dilerent spacing between the sensing pins of various denominations is necessary: the notches representing pence values must not be aligned with pins 24 associated with shillings or pounds register wheels, and vice versa. Similarly, notches representing pounds values must not b e aligned with sensing pins associated with denominations of fractions of a penny, and vice-Versa.

Considering the shift of the DHS) selector plate to the right into position 1, 2, 3, or -4, only one notch in this plate, namely that representing 3, will be aligned with sensing pin Dill-1, DIG-2, Di0-3, or Dill-4, respectively, Thus, the value 03d., or 0.03d., or 0.003d., or 0.0003d., as the case may be, will be entered into the register.

Those sensing pins 24 which are not aligned with any selector plate l (i. e., the Dill-2 pin when the plate Dl (3) is in the +7 position) are rendered inoperative by means which will be described in due course.

Considering now the selector plate L|0(I), in the initial position 0 only one notch designated 1, which is one step deep, is aligned with a sensing pin, namely that of the LIB denomination. Consequently, the amount 10 will be registered. When this plate is shifted to the left, this same notch l will be aligned with pins 24 of the higher pounds denominations LN2-M08; thus 100, 1,000, 10,000 and so forth will be registered. when the plate is in DOSOIl -I-l, +2, +3, and so forth, respectively. In position 1 this notch, being aligned with the Ll pin, will cause itv to register 1. When the plate is in position 2, this notch l is not aligned with any pin 24; instead, another notch 2, which is two steps deep, will be aligned with the Sl sensing pin which thus enters into the register 2 =10 0.01. In position -3 notches "2 and 4 will be aligned with pins DI, DIS-1 respectively, which will register 2.4d.=10 0.00l. Finally, in position -4 notches "2 and 4 will col-act with pins Dlllrl and Dill-2, respectively, to enter into the register 0.24d.=10 0.0001,

The arrangement of the selector plate M0401) will be readily understood, in the light oi the above explanation, from an inspection of Figure 9. Other selector plates l0 are notched similarly to represent the respective decimal multiples eX- pressed in the final denominations. it will be noted that if a notch represents a digit of a decimal set of units (pounds or decimals of a penny), this notch may be aligned, due to carriage shift, with sensing pins of several denominations of this set of units, but if a notch represents a digit of a non-decimal denomination (tens of shillings, or units of shillings, or pence), this notch will be aligned only with the sensing pin of this particular enomination. Similarly, notch representing a pounds value may be aligned with any sensing pin yassociated with a pounds denomination but never with a sensing pin associated with a denomination of fractions of a penny, and vice-versa.

All notches in the various selector plates of the same bank are sensed simultaneously, as will be described hereafter. Thus, assuming it is desired to multiply 40,010:0:3d. l0.001, the setting levers Ll 04, L10, and DI are adjusted in line with numerals 4, 1, and 3 o-n carriage cover l0, respectively. Thus, selector plates shown in Figure 9 are brought into working position in alignment with sensing pins 24 of the lower bank. The carriage is then shifted into position +1, and the decimal multiple 400,100Z226d.=40,010:023d. 10

isregistered as described above. The carriage is then shifted into position 3, and the amount 40:0:2.403d.=40,010:0:3d. 0.001 is added to the register, which will show the result as the sum of these two decimal multiples, namely The converted values of all decimal multiples oi the set-up values within the capacity of the machine are shown in Figure l (for pence), Figure 2 (for shillings), and Figure 3 (for pounds). Columns -2, 3, -4 in Figure l are left blank as the numerical values of the respective decimal multiples are identical with those of column 1, the decimal point being shifted in each successive column one step to the left. It will be understood that although all values shown in Figures 1-3 are represented by notched selector plates I6, the total number of notches in plates I6 is considerably less than the number of digits contained in Figures 1-3, since one and the same notch may represent a digit of several denominations of a decimal set of units. Thus, a single notch designated 4 on plate M040!) in Figure 9 may represent, according to the position of the carriage, 40,000 or 4,000 or 4, and so forth.

Selector plates I6 of the upper, centre, and lower bank are shown in Figures 10, 11, 12, respectively. In these figures, the vertical lines of numerals designate the set-up. values associated with respective selector plates; the dotted vertical lines approximately in the middle of the drawings indicate the position of the DI sensing pin 24,

The capacity of the machine made according to the invention is not limited to that specified above. Both the number of carriage shifts (which determines the multiplier) and the number of denominational sets of selector plates (which determines the set-up factor, e. g. multiplicand) may be increased or decreased as desired. The notches in the selector` plates may be arranged to suit not only the pounds sterling system of notation, but any other numerical system, for instance the avoirdupois system, Indian currency, and so forth. In a modified conversion mechanism made according to the present invention the selector plates D10-1 and DIIJ-Z may be replaced by sixteen selector plates representing the decimal multiples of vulgar fractions le- {L- of a penny. These multiples are shown in Figure 4, columns -4 to l of which are left blank for the same reason `as stated with reference to Figure 1. The corresponding selector plates are shown in Figure 13, wherein Df signifies fractions of a penny denomination. It is evident that with suitable alterations the selector plates Df may be made to represent any other fractions instead of sixteenths.

Feelcr mechanism As already described, the notched selector plates iB determine the amount of movement of sensing pins 24 during the working cycle of the machine. As shown in Figures 6, 6A, sensing pins 24 co-act with three-pronged feelers 41 pivoted at 48 in gear sectors 49 rockable on a shaft D fixed in the supporting structure 2, 3 (see also Figures 7, 7A). Each gear sector 49 co-operates with a numeral wheel of the result register as will be described hereafter. Rockably mounted on shaft 50 adjacent to each gear sector 49 is a bracket 5I which has a pin 52 engaging a slot in gear sector 49 (see also Figure 14); a spring 53 connects each sector with its bracket. A stronger spring 54 anchored in a spring bar 55 tends to swing each bracket 5l anti-clockwise as viewed in Figure 6A, so that an abutment I56 thereon abuts against a restoring bar 51. This bar is common to all brackets 5l; it extends across the machine and is at each end pivotally mounted on shaft 5U, a spring 58 keeping a roller 59 journalled at each side of bar 51 in contact with a triple cam E3. Thus, during each revolution of cams 3D the brackets 5| and gear sectors 49 are reciprocated three times.

A link 6l is pivoted at 62 to each feeler 41. The lower ends of links 6I are pivoted on a common rod 63 supported in a bar 54 rockable on shaft 50; a roller 55 journalled at either end of bar 64 is biased on to a cam 66 by a spring 61. Cams 6G are so shaped as to rock the feelers 41 prior to the first forward (anti-clockwise) movement of brackets 5I and gear sectors 49 so that the upper prongs 68 of feelers 41 are aligned with the upper bank of sensing pins 24, whereas the two lower prongs are not aligned with their respective banks of pins 24; prior to the second forward movement feelers 41 are rocked so that the middle prongs 69 are aligned with the middle bank of pins 24, as shown in Figures 6, 6A; nal- 1y, prior to the third forward stroke of feelers 41 they are rocked by cams 66 so that their lower prongs 10 are aligned with the lower bank of pins 24, the other prongs 68, 69 being out of alignment with their respective banks of sensing pins 24. Thus, during a complete revolution of cams B0, 66, the three banks of pins 24 are contacted in succession by feelers 41 and pushed forward into the notches of selector bars I6. As the extent of movement of pins 24 is determined by the depth of notches they encounter, the amount of movement of feelers 41, gear sectors 49, and brackets '5I is also determined by these notches in the selector plates; consequently, the amount of movement imparted by each gear sector 49 to the register wheel which it drives in a manner to be described hereafter is also determined by the numerical values represented by the respective notches.

Shaft 50, rod E3, and pivots 48, 62 form a parallelogram, so that prongs 68, 69, 10 of feelers 41 are reciprocated along parallel and substantially straight lines. Guides 1|, 12 serve to ensure proper alignment of the feelers 41 with sensing pins 24.

The reason for the three-bank arrangement of selector plates l5 and sensing pins 24, and for the successive reading-out of these three banks by a triple movement of feelers 41 and gear sectors 49 will be apparent after the following consideration. Assuming it is desired to multiply llld. set up as 1.25d. by 100, all three sub-products: 1d. l00=8/4d.; 0.2d. l00=1/8d.; 0.05d. 1 00=5d.; contain pence values to be entered into the same register wheel DI. Evidently, this cannot be done simultaneously; each subproduct must be registered separately, the Whole operation to obtain the result 10/5d. being completed in three successive steps.

Prongs 68, 69, 10 on feelers 41 are so shaped that when they are rocked into alignment with their respective sensing pins 24, the latter are pushed forward slightly until they encounter the edge of a selector plate I5, or just begin to enter a notch therein, as the case may be. When the feelers 41 are released for forward movement by cams ED, those feelers which are stopped by their sensing pins encountering the edge of a selector plate IG do not move appreciably, but their associated brackets 5I move a distance determined by the length of slots engaged by pins 52 in gear sectors 49, whereupon the brackets 5| are also stopped. This slight independent movement of brackets 5i is utilised to effect the carrying operation as will be described hereafter.

Sensing pins 24 are restored after each forward stroke of feelers 41 by a restoring plate 13 iixed at each side of the machine to a slide 14. Slots in slides 14 embrace guide pins 15 secured to side plates 2, 3. Pin 16 fixed to each slide 14 is engaged by a fork 11 fixed at each end of the restoring bar 51 operated by cams 60 as described above. Thus, when bar 51 and feelers 41 begin to move forward, the restoring plate 13 also moves forward to allow for free movement of sensing pins 24. On return stroke the plate 13 engages shoulders 18 formed on pins 24 and restores them to initial position shown in Figure 6.

Gear sectors 41 have lower extensions 19 adapted to co-act with locking pawls pivoted in a bar 8| xed to base plate I. Springs 82 b-ias the pawls 8l into engagement with extensions 19, thus locking the gear sectors 41 and preventing their forward movement when released by cams 60. Locking pawls 8D are controlled by a plate 83 fixed to carriage base 9. The arrangementJ is such that when the carriage 5 is aligned with certain gear sectors 49, the plate 83 rocks the respective pawls 80 to unlock these gear sectors 49 for co-operation with the selector 

